The Regional Adaptation of Corn in Nebraska 5 
area. This stoma tal character is associated with a rather cor- 
responding reduction in size of epidermal cell, all of which 
may be ascribed to a more dwarfish development. The number 
of vascular bundles per unit cross-section of leaf is fairly con- 
stant. 
While some of the vegetative characters, such as total leaf 
area and plant weight, may reduce as much as 300 per cent, 
no important histological leaf characters exhibit more than 15 
per cent deviation in the case of native types growing in the 
most adverse as compared with the most favored parts of the 
State. 
Practically speaking, adaptation with corn consists in a 
morphological rather than in a histological reaction. 
As a concrete example of the foregoing adaptive reactions, 
the 1915 difference between home-grown native Richardson 
County and Kimball County corn types may be cited. These 
two localities represent the extremes of corn growing conditions 
within the State. Comparing the measurements of Richardson 
County corn with those of Kimball County corn, we have the 
following ratios : Stalk height, 100 :60 ; ear height, 100 :35 ; leaf 
area, 100:36; stover weight, 100:49; ear weight, 100:24; grain 
weight, 100:20; total plant substance, 100:34; shelling per- 
centage, 100:84; leaf area, per unit dry matter, 100:100; ear 
length, 100 :65 ; ear circumference, 100 :81 ; kernel length, 100 :73 ; 
leaf thickness, 100:96; thickness of upper epidermis, 100:97; 
thickness of lower epidermis, 100 :97 ; number of vascular 
bundles per unit of cross-section of leaf, 100:104; number of 
stomata per square millimeter of upper epidermis, 100:113, 
and of lower epidermis, 100:115; length of stoma of upper 
epidermis, 100:89, and of lower epidermis, 100:90; length of 
epidermal cell of upper epidermis, 100:92, and of lower epi- 
dermis, 100 :97 ; and width of epidermal cell of upper epidermis, 
100:99, and of lower epidermis, 100:92. 
The immediate effect of moving corn from its native en- 
vironment to less favorable conditions, climate being the chief 
variable factor, is generally a reduction in both vegetative 
growth and grain production. The stunting growth effect ex- 
tends to the cell unit, which in turn is accompanied by histo- 
logical changes that can not apparently be regarded as of an 
adaptive nature. These changes may be illustrated by com- 
parison of native Lancaster County corn when grown at: home 
and when grown in the more adverse region of Kimball County. 
Using the Lancaster County crop as a basis, the relative re- 
sults were as follows: Plant height, 100 and 80; ear height, 100 
and 52; leaf area. 100 and 78; stover weight, 100 and 62; ear 
weight, 100 and 1; grain weight, 100 and 0.8; total dry matter, 
